Self-amplified Cherenkov radiation from a relativistic electron in a waveguide partially filled with a laminated material

The radiation from a relativistic electron uniformly moving along the axis of cylindrical waveguide filled with laminated material of finite length is investigated. Expressions for the spectral distribution of radiation passing throw the transverse section of waveguide at large distances from the laminated material are derived with no limitations on the amplitude and variation profile of the layered medium permittivity and permeability. Numerical results for layered material consisting of dielectric plates alternated with vacuum gaps are given. It is shown that at a special choice of problem parameters, Cherenkov radiation generated by the relativistic electron inside the plates is self-amplified. The visual explanation of this effect is given and a possible application is discussed.Comment: 8 pages, 4 figures,1 table, the paper is accepted for publication in the Journal of Physics: Conference Serie

Performance of the Electromagnetic Calorimeter of the HERMES Experiment

The performance of the electromagnetic calorimeter of the HERMES experiment is described. The calorimeter consists of 840 radiation resistant F101 lead-glass counters. The response to positrons up to 27.5 GeV, the comparison between the measured energy and the momentum reconstructed from tracking, long-term stability, hadron rejection and neutral meson invariant mass reconstruction are shown.Comment: 22 pages, 13 figures, LaTeX, accepted by NI

Some features of electromagnetic field of charged particle revolving about dielectric ball

A relativistic electron uniformly rotating along an equatorial orbit around a dielectric ball may generate Cherenkov radiation tens of times more intense as that in case of revolution of a particle in a continuous, infinite and transparent medium. The root-mean-square values of electric and magnetic field strengths of particle are practically not localized in the central part of the equatorial plane of ball and close to the poles of ball.Comment: 6 pages, 3 figures, contribution to Proceedings of International Symposium RREPS-2009, 07-11 September, 2009, Zvenigorod, Russi

Ghosts Also Die: Resisting Disappearance through the 'Right to the Truth' and the Juicios por la Verdad in Argentina

This paper attempts to provide a more complete understanding of the so-called right to the truth, deriving from court-made doctrine in the human rights field, and associated with an alternative form of legal proceeding in Argentina that has no equivalent anywhere else in the world: the trial for the truth (juicio por la verdad), a procedure sui generis created in the aftermath of the military dictatorship in response to both the politics of forgetting that prevailed in the 1990s and the continuing obstruction of criminal proceedings down to 2003 due to amnesty laws. Protecting the right to the truth fulfils three functions by turns: first, it makes possible conciliation of amnesty with the right to judicial protection; second, it constitutes the condition for real access to justice; third, it validates the reality of the crime. Each of these functions is associated with one of the three elements, which, together, comprise the struggle against impunity: investigation, sanction, and reparation. Situated between truth commissions and classic criminal proceedings, symbolic reparation and retribution, the Argentinian trials for the truth offer a new way of conceiving both the criminal-law judge's mission and the relations among law, truth, history, and memory in the context of the rich debates about (post-)transitional justice